In-depth interview assumes conducting a detailed, thorough conversation with the respondent. During the interview, a specialized researcher uses a fixed scheme of threads that make up the interview script.
The purpose of the interview is to broaden knowledge on the topic of interest by asking exploratory questions that help explain and understand the issue of interest. Therefore, an important element of the interview is the complete freedom of the interviewee’s speech and conducting the conversation in such a way that all issues are covered.
An in-depth interview is often used when discussing difficult or intimate topics, and also when we expect a negative impact of the group on the respondents’ statements and we do not care about confronting the respondents’ opinions. IDI is also useful in the study of hard-to-reach groups, e.g. experts or people in high or geographically dispersed positions.
In in-depth interviews, aiding and projection techniques may be helpful, which, by means of visual materials or associations, allow for an in-depth interpretation of the respondent’s statements. Thanks to in-depth interviews, it is possible not only to learn about individual experiences, mechanisms and motives for making decisions, but also to accurately describe the reasons for actions, opinions and attitudes towards products and services, as well as to understand the respondent’s perception of social phenomena or brand.